1. Technical Field
The present invention relates to a method of manufacturing a display including microcapsules, and an electronic apparatus including a display obtained by this manufacturing method.
2. Related Art
As the related art, electrophoretic displays that have an electrophoretic dispersion liquid including a liquid dispersion medium and electrophoretic particles have been known. The electrophoretic displays utilize optical characteristic changes of the electrophoretic dispersion liquid resulting from distribution changes of the electrophoretic particles caused by application of an electric field. Such electrophoretic displays need no backlight and thus permit lower costs and a thinner form. In addition, the electrophoretic displays offer a wide viewing angle and a high contrast, and allow memorization of a displayed image. Therefore, the electrophoretic displays have been a focus of attention as a next-generation display.
For the electrophoretic displays, a method has been proposed in which an electrophoretic dispersion liquid is encapsulated in microcapsules. For example, Japanese Unexamined Patent Publication No. 1-86116 discloses an example of this method. This encapsulation of an electrophoretic dispersion liquid in microcapsules provides advantages of preventing the effusion of the dispersion liquid caused in manufacturing steps of the display, and reducing sedimentation and aggregation of the electrophoretic particles.
Typically such an electrophoretic display including microcapsules is fabricated as follows: A whole surface of a substrate having a common electrode thereon is coated with microcapsules. Another substrate having pixel electrodes thereon is applied to the microcapsule-coated surface to laminate the substrate. For example, this fabrication method is disclosed in Japanese Unexamined Patent Publications No. 2002-318396 (paragraph [0003], in particular) and No. 2002-532756 (FIG. 7B, in particular), and SID98DIGEST pp. 1014–1017.
A method is also known in which microcapsules are ejected one by one on pixel electrodes from ink jet nozzles. For example, Japanese Unexamined Patent Publication No. 2000-35769 discloses an example of this method.
However, the above-described method of coating a whole surface of a substrate having a common electrode thereon with microcapsules has the following disadvantages.    (1) Since a whole surface of a substrate is coated with microcapsules, areas other than a display area contributing to actual display are needlessly coated with the microcapsules, resulting in a waste of part of the material.    (2) In the case of manufacturing a display by applying substrates to each other, typically formed on one substrate are conductive parts for applying a voltage to electrodes of the other substrate. Subsequently, the substrates are applied to each other so that the conductive parts are electrically coupled to the electrodes of the other substrate. Therefore, also in the above-described example, typically a conductive part is formed on a substrate having pixel electrodes thereon in advance, and then the substrate having the pixel electrodes is applied to a substrate having a common electrode so that the conductive part is electrically coupled to the common electrode. However, a whole surface of the substrate having the common electrode is coated with the microcapsules. Therefore, the microcapsules need to be removed from part to be electrically coupled to the conductive part before the applying of the substrates. In order to remove the microcapsules, a method of mechanically removing, or a method of chemically removing with a solvent or the like is used, for example. However, either method may damage the underlying common electrode, with the result that the display characteristics of the manufactured display are deteriorated. Furthermore, the removal of the applied microcapsules leads to a waste of the material.    (3) After the applying of the substrates, typically sealing is implemented between the peripheral parts of the substrates in order to protect the electrodes and microcapsules from moisture and so on. However, if the part to be sealed is coated with the microcapsules, the sealability between the substrates is lowered. Therefore, the microcapsules on the peripheral part of the substrate also need to be removed before the applying of the substrates. This removal of the microcapsules, however, results in the same disadvantages as those described in (2).
In addition, in the above-described method of ejecting microcapsules one by one from ink jet nozzles onto pixel electrodes, the applying time is problematically long and thus the productivity is low since a number of microcapsules need to be ejected and applied.